The Correct Order to Hook Up Jumper Cables

Connect in this sequence: red clamp to the dead battery’s positive (+) terminal, red clamp to the donor battery’s positive (+), black clamp to the donor battery’s negative (–), and black clamp to an unpainted metal ground on the disabled vehicle (not its negative terminal). Start the donor, then start the disabled vehicle, and remove the cables in reverse order. This approach minimizes sparks near the battery and aligns with most automaker guidance for modern vehicles.

Why the Order Matters

Jump-starting a vehicle seems simple, but batteries release flammable hydrogen gas and modern cars often include sensitive battery sensors. Using the correct sequence reduces the risk of sparks near the battery, protects electronics, and increases the odds of a successful start. Always consult your owner’s manual for vehicle-specific jump points, as many cars now provide dedicated under-hood terminals.

Connection Order: How to Hook Up the Cables

Follow these steps to attach the jumper cables safely and correctly. Ensure both vehicles are in Park (or Neutral for manuals), parking brakes engaged, and ignitions off before making connections.

1. Attach the red (+) clamp to the disabled vehicle’s positive (+) battery post or designated positive jump terminal.
2. Attach the other red (+) clamp to the donor vehicle’s positive (+) battery post or positive jump terminal.
3. Attach the black (–) clamp to the donor vehicle’s negative (–) battery post.
4. Attach the remaining black (–) clamp to a solid, unpainted metal ground on the disabled vehicle—ideally an engine block bolt or a manufacturer-designated ground point—well away from the battery and fuel system. Do not clamp to the dead battery’s negative post.

This sequence keeps any arcing away from the battery where gas may be present and respects the design of modern charging systems, which often include a battery sensor on the negative post.

Starting Procedure and What to Expect

Once the cables are connected, bring the disabled battery up to a charge that’s sufficient to crank the engine without overstressing either vehicle’s electrical system.

1. Start the donor vehicle and let it run at about 1,200–1,500 rpm for 2–5 minutes to pre-charge the disabled battery.
2. Try to start the disabled vehicle. If it cranks slowly, wait another 2–3 minutes and try again. If there’s no crank or only clicking after multiple attempts, recheck connections or consider that the battery or starter may be faulty.
3. Once the disabled vehicle starts, let both vehicles idle connected for 60–120 seconds to stabilize voltage before disconnecting.

If the disabled vehicle will not start after 10–15 minutes of charging attempts, stop and investigate further. Persisting can overheat cables or damage electronics.

Disconnection Order: Remove Cables in Reverse

Taking the cables off in the reverse sequence prevents shorts and keeps sparks away from the battery.

1. Remove the black (–) clamp from the grounded metal point on the revived vehicle.
2. Remove the black (–) clamp from the donor vehicle’s negative (–) post.
3. Remove the red (+) clamp from the donor vehicle’s positive (+) post.
4. Remove the red (+) clamp from the revived vehicle’s positive (+) post.

After disconnecting, keep the revived vehicle running for at least 15–30 minutes or drive it to allow the alternator to replenish the battery. A smart charger can more fully recharge and test battery health.

Safety Checks and Good Practices

These precautions reduce risk to you and your vehicle’s electronics and improve the likelihood of a successful jump-start.

• Confirm both vehicles use 12-volt systems; do not jump a 12V car with a 24V truck system.
• Inspect batteries: do not jump if the case is cracked, leaking, or frozen (a frozen battery must be thawed and tested).
• Remove metal jewelry and keep cables clear of belts, fans, and hot components.
• Match polarity carefully: red to +, black to –. A brief reversal can damage ECUs and charging systems.
• Use the chassis/engine ground on the disabled vehicle, especially if it has a battery sensor (common on the negative terminal in modern cars).
• Use adequately thick cables (4- or 6-gauge for most cars; 2-gauge for trucks) with clean clamps for better current flow.
• If the vehicle has start-stop or AGM/EFB batteries, use the manufacturer’s jump posts and procedures noted in the owner’s manual.

Adhering to these practices not only improves safety but also helps protect sensitive electronics common in newer vehicles.

Special Cases: Hybrids, EVs, and Modern Systems

Different drivetrains and battery technologies can change the right approach, and using the wrong method can cause costly damage.

• Hybrids and EVs have a 12V system for accessories; many can be jump-started, but always use the specified jump posts. Do not use most EVs to jump-start another vehicle unless the manual explicitly allows it.
• Vehicles with intelligent battery sensors (IBS) on the negative terminal require using the designated ground point; clamping to the negative post can bypass the sensor and upset charging logic.
• If the disabled car repeatedly needs jumps, the battery may be at end-of-life or the alternator may be failing; get a load test and charging system check.

Consult the owner’s manual for your specific vehicle—manufacturers sometimes provide unique terminals or steps tailored to their systems.

Using a Portable Jump Starter

A portable jump pack follows the same clamp order but removes the need for a donor vehicle. Make sure the pack is charged and rated for your engine.

1. Turn off the vehicle and accessories; connect red (+) clamp to the dead battery’s positive (+) post or jump terminal.
2. Connect black (–) clamp to a solid, unpainted metal ground on the vehicle (not the negative post).
3. Power on the jump pack (if required) and start the vehicle. If it doesn’t start, wait 30–60 seconds and try once more.
4. Turn off the jump pack, remove the black (–) clamp first, then the red (+) clamp.

Store the jump pack indoors when not in use and recharge it after every use so it’s ready for emergencies.

Summary

The correct order to hook up jumper cables is: red to the dead battery’s positive, red to the donor’s positive, black to the donor’s negative, and black to a solid ground on the dead vehicle. Start the donor, then the disabled vehicle, and disconnect in reverse: ground off the revived car, donor negative, donor positive, revived car positive. Use designated jump points, avoid sparks near batteries, and follow your owner’s manual—especially for hybrids, EVs, and vehicles with battery sensors.

Do I connect black or red first?

When connecting jumper cables to a car with a dead battery, always connect the red/positive cable first to the positive (+) terminal of the dead battery, and then to the positive terminal of the working battery. The negative (black) cables should be connected last, with one to the negative terminal of the working battery and the other to an unpainted metal surface on the dead car’s engine block or frame to complete the circuit.
 
This video demonstrates how to safely connect jumper cables to a car battery: 51sStan CravensYouTube · Oct 9, 2018
Step-by-Step Guide to Connecting Jumper Cables:

1. Turn off both vehicles: Opens in new tabEnsure the ignition keys are in the off position in both the car with the dead battery and the donor car. 
2. Connect the red (positive) cable to the dead battery: Opens in new tabAttach one red clamp to the positive (+) terminal of the dead battery. 
3. Connect the red (positive) cable to the donor battery: Opens in new tabAttach the other red clamp to the positive (+) terminal of the good battery on the donor vehicle. 
4. Connect the black (negative) cable to the donor battery: Opens in new tabAttach one black clamp to the negative (-) terminal of the donor vehicle’s good battery. 
5. Connect the black (negative) cable to the dead car’s frame: Opens in new tabAttach the final black clamp to an unpainted, unmoving metal part of the engine block or frame of the car with the dead battery. A slight spark may occur, which is normal. 

Why this order?

• Red first: Connecting the positive (red) cable to both batteries first creates a complete circuit without completing the negative side. 
• Last connection to metal: The last black clamp is attached to an unpainted metal surface on the dead car’s frame, not the negative terminal. This minimizes the risk of sparks, as the battery releases hydrogen gas that could cause an explosion. 

Does the order you put jumper cables on matter?

Yes, the order of connecting jumper cables matters for safety, primarily to prevent sparks and potential damage to the vehicles’ electronics. The correct sequence involves connecting the red (positive) clamps to both car batteries first, then the black (negative) clamp to the donor car’s negative terminal, and the final black clamp to an unpainted metal surface on the dead car’s chassis, away from the battery. Disconnecting should be done in the reverse order.
 
This video explains how to jump start a car safely with jumper cables: 1mStan CravensYouTube · Oct 9, 2018
Connecting the Cables

1. Position the cars: Place the vehicles close enough for the cables to reach, but ensure they are not touching. 
2. Turn off both cars: Ensure both engines are off. 
3. Connect the red (positive) clamps: Attach one red clamp to the positive (+) terminal of the dead battery, and the other red clamp to the positive (+) terminal of the working battery. 
4. Connect the black (negative) clamps: 
   • Attach one black clamp to the negative (-) terminal of the working battery. 
   • Attach the other black clamp to an unpainted metal part of the dead car’s frame or engine block, away from the battery. 
5. Start the working car: Let it run for a few minutes to charge the dead battery. 
6. Start the dead car: After a couple of minutes, try to start the car with the dead battery. 

This video demonstrates the proper connection process with jumper cables: 1mDilawriYouTube · Jan 11, 2018
Disconnecting the Cables
The cables should be removed in the exact reverse order of how they were connected to ensure safety: 

1. Disconnect the black clamp: from the dead car’s metal surface. 
2. Disconnect the black clamp: from the working car’s negative terminal. 
3. Disconnect the red clamp: from the working car’s positive terminal. 
4. Disconnect the red clamp: from the dead car’s positive terminal. 

This video shows how to safely disconnect jumper cables: 34sExpertVillage Leaf GroupYouTube · Dec 12, 2020

What is the correct order to attach jumper cables?

It goes like. This red to the dead. Red to the good black to the good. Then under the hood. Now let’s watch as Brian from Henderson Auto puts all of that into action.

Is there an order for putting on jumper cables?

Make sure you have followed these steps in proper order: red clip from booster cable to positive terminals, then black clip from booster cable to negative terminals. Once all connections are made, start up your working vehicle and let it run for a few minutes before attempting to start your dead battery’s engine.